in cdDriv the following:
if( vary.lgVaryOn )
{
	if( lgTraceInput )
		fprintf( ioQQQ, "cdDriv: calling DoOptimize\n");
	/* option to drive optimizer set if OPTIMIZE was in input stream */
	DoOptimize();
}
else
{
	if( lgTraceInput )
		fprintf( ioQQQ, "cdDriv: calling cloudy\n");
	/* optimize did not occur, only compute one model, call cloudy */
	cloudy();
}

DoOptimize chooses which optimization routine to call